The goal of this research program is to develop a novel fiber-based source for coherent Raman scattering (CRS) microscopy. We will develop a fiber-based picosecond source tunable from 800 nm to 910 nm and an all-fiber time-lens synchronized source at 1064 nm, and then demonstrate the value of the proposed laser system for CRS microscopy. The proposed source is based on two major innovations: (1) soliton self-frequency shift (SSFS) in a large mode area (LMA) fiber that enables the generation of energetic, wavelength tunable soliton pulses seeded by a fiber laser at the telecom wavelength (~ 1550 nm), and (2) time-lens pulse compression and synchronization that enables an all-fiber picosecond source to synchronize to a mode- locked laser at arbitrary repetition rate. Leveraging the highly mature and integrated techniques that have been developed for the telecommunications industry, we aim to create a "telecom grade" synchronized source that is truly robust and turn-key, and tailored specifically for biomedical research and clinical diagnostics. The successful completion of this program will facilitate the widespread applications of CRS imaging in biomedical research. PUBLIC HEALTH RELEVANCE (provided by applicant): The proposed program, if successfully completed, leads to a novel, fiber-based synchronized source that will have a broad impact on biomedical applications of ultrafast technologies. There are significant practical advantages offered by the fiber configuration, such as compact foot print, robust operation, lower cost, and operational safety in a clinical environment. The successful completion of this research program will make synchronized picosecond sources widely accessible to biologists and medical researchers and practitioner.